Ichiro Matsunaga

Relationship between active and passive smoking and total serum IgE levels in Japanese women: Baseline data from the Osaka Maternal and Child Health Study

Background: Many studies have shown that cigarette smoking is associated with elevated concentrations of total serum IgE. Few studies, however, have examined total IgE in relation to passive smoking exposure, especially in adults. This cross-sectional study investigated the association of active and passive smoking exposure with levels of total serum IgE in Japan. Methods: Study subjects were 981 pregnant women in Osaka. Total IgE levels were measured using UniCAP 1000 and were defined as elevated if they exceeded 170 ml/UI. Age, gestation, parity, family history of asthma, atopic eczema and allergic rhinitis, indoor domestic pets, family income, education and the mite allergen level in house dust were selected as potential confounding factors. Results: Current smoking of at least 15 cigarettes a day and 8.0 or more pack-years of smoking were independently related to an increased prevalence of elevated total serum IgE (adjusted odds ratios 3.40 and 2.51, 95% confidence intervals 2.12–5.47 and 1.55–4.06, respectively), and both cigarette smoking status and pack-years of smoking were significantly positively associated with total serum IgE levels, especially in subjects with a positive familial allergic history. There was no measurable association of exposure to environmental tobacco smoke (ETS) at home or at work with total serum IgE concentrations among those who had never smoked. Conclusions: Our results corroborate a positive relationship between active smoking and total serum IgE levels; however, this study failed to substantiate a positive association of ETS exposure with total IgE. Investigations with more precise and detailed exposure measurements are warranted.

A LUNG MODEL DESCRIBING UPTAKE OF ORGANIC SOLVENTS AND ROLES OF MUCOSAL BLOOD FLOW AND METABOLISM IN THE BRONCHIOLES

A simple lung model (mucosal blood flow and metabolism model, MBM model) was developed to describe the uptake of organic solvents and investigate the role of mucosal blood flow and metabolism. The model separates the lung into four compartments, the peripheral bronchial tract (gas phase), the mucus layer lining the wall surface of the tract, the alveolar space (gas phase), and the alveolar blood. Solvent molecules are absorbed in the mucus layer during inhalation and released during exhalation. The deposited solvent diffuses radially into the mucosal tissue of the respiratory tract and transfers to the mucosal blood flow. To describe this behavior, a hypothetical mucosal blood flow throughout the mucus layer was used. The solvent in the mucosal tissue may be also metabolized, and a hypothetical metabolism in the mucus layer was used. The rate of the hypothetical mucosal blood flow was determined to be 5.2 ml/min based on the best fitting of previously obtained data for seven polar organic solvents. The MBM model predicts that as the blood? air partition coefficient (lB) increases from 0.1 to 20, the relative end-exhalation (E end) will decrease from 0.89 to 0.07, and as l B increases to 500, Eend will increase to 0.33. After l B = 500, E end is predicted to decrease again, and at l B = 10000, E end is 0.09. The model also predicts that as l B increases from 0.1 to 10, the relative uptake (U) increases from 0.08 to 0.61, and as l B increases to 150, U decreases to 0.50. After l B = 150, U increases again, and at l B = 10,000, U is 0.8. The predictions show good agreement with values observed in human experimental studies. The MBM model predicts that uptake by the mucosal blood (U Al) would be equal to uptake by the alveolar blood (U Mu) at l B of 1000 and UAl is more than 90% of total uptake at l B > 10,000. The model also shows that U is significantly increased by the mucosal metabolism at l B between 50 and 5000. Especially, U in the case of CLMu = 100 ml/min is higher by 0.3 than that in the nonmucosal metabolism.

Interior Air Pollution in Automotive Cabins by Volatile Organic Compounds Diffusing from Interior Materials: I. Survey of 101 Types of Japanese Domestically Produced Cars for Private Use

The types and concentrations of organic compounds in the interior air of 101 different types of Japanese domestically produced private-use cars were examined. All the vehicles had been registered in the summer season as new cars and were less than 3 years old. The airborne compounds in the cabins were collected for 24h under static condition with the engine stopped and the windows, doors and vents closed. A total of 275 organic compounds, including many aliphatic hydrocarbons and aromatic hydrocarbons, were identified, and 242 of them could be quantitated for each cabin. The sum of the concentrations of 241 compounds excluding formaldehyde was approximately 600 g·m-3 as a median, ranging from 136 to 3968 g·m-3 for the tested cars. The findings demonstrated that the air in the cabin of these cars was contaminated by high concentrations of a large variety of organic compound diffusing from the interior materials.

Association of active and passive smoking with allergic disorders in pregnant Japanese women: baseline data from the Osaka Maternal and Child Health Study

BACKGROUND Evidence remains inconclusive as to whether smoking is a risk factor for allergic disorders in adults. OBJECTIVE To investigate the relationship between active and passive smoking exposure and allergic disorders in pregnant Japanese women. METHODS This cross-sectional study included 1,002 pregnant women. Participants were classified as having asthma after the age of 18 years if they had used an asthma medication at any time after reaching the age of 18 years. Current atopic eczema and allergic rhinitis (including cedar pollinosis) were defined as being present if participants had received any drug treatment during the previous 12 months. Adjustment was made for age; gestation; parity; family history of asthma, atopic eczema, and allergic rhinitis; indoor domestic pets; family income; education; and the mite antigen level in house dust. RESULTS Current smoking, but not environmental tobacco smoke exposure, was independently related to an increased prevalence of asthma after the age of 18 years (adjusted odds ratio [OR], 2.66; 95% confidence interval [CI], 1.30-5.38). A significant positive association of current passive smoking exposure at home (adjusted OR, 1.89; 95% CI, 1.10-3.30) and at work (adjusted OR, 2.50; 95% CI, 1.29-4.76) with the prevalence of current allergic rhinitis was observed, whereas no measurable association with active smoking exposure was found. Neither active nor passive smoking was statistically significantly related to the prevalence of current atopic eczema. CONCLUSIONS These findings suggest that active smoking and environmental tobacco smoke exposure may increase the likelihood of asthma and allergic rhinitis, respectively, in pregnant Japanese women.

Fish and Fat Intake and Prevalence of Allergic Rhinitis in Japanese Females: the Osaka Maternal and Child Health Study

Objective: It remains uncertain whether intake of fish or n-3 polyunsaturated fatty acids is preventive against allergic disorders. This cross-sectional study investigated the association of intake of selected high-fat foods and specific types of fatty acids with the prevalence of allergic rhinitis in Japan where intake of fish is high. Methods: Study subjects were 1002 Japanese pregnant females. Allergic rhinitis (including cedar pollinosis) was defined as present if subjects had received drug treatment at some point during the previous 12 months. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for age, gestation, parity, cigarette smoking, passive smoking at home and at work, indoor domestic pets, family history of asthma, atopic eczema, and allergic rhinitis, family income, education, mite antigen level in house dust, changes in diet in the previous month, season when data were collected, and body mass index. Results: There was a tendency for an inverse dose-response association between fish intake and allergic rhinitis although the adjusted odds ratio for comparison of the highest with the lowest quartile was not statistically significant (p for trend = 0.09). Intake of eicosapentaenoic and docosahexaenoic acids was independently associated with a decreased prevalence of allergic rhinitis: the multivariate odds ratio for the highest quartile was 0.56 (95% confidence interval: 0.32–0.96, p for trend = 0.03). Intake of n-6 polyunsaturated fatty acids in the third quartile but not the second and fourth quartiles showed a tendency for an inverse association with the prevalence of allergic rhinitis. No measurable relationship was found between consumption of meat, eggs, dairy products, total fat, saturated, monounsaturated, and n-3 polyunsaturated fatty acids, and cholesterol or the ratio of n-3 to n-6 polyunsaturated fatty acids and allergic rhinitis. Conclusion: Our findings suggest that the intake of eicosapentaenoic and docosahexaenoic acids may be associated with a reduced prevalence of allergic rhinitis.

APPLICATION OF INVERSE GAUSSIAN DISTRIBUTION TO OCCUPATIONAL EXPOSURE DATA

Abstract Occupational exposure concentrations are generally assumed to vary in a log-normal manner. However, because the mean of random samples from a log-normal distribution is not lognormally distributed, it cannot, in theory, deal with the changes in the distribution of timeweighted average (TWA) values when the averaging time varies. On the other hand, inverse Gaussian distribution, which is similar to a log-normal one, offers the advantage of reproducibility. This paper proposes the application of inverse Gaussian distribution to occupational exposure data. First, inverse Gaussian distribution was compared with the log-normal one. Second, in order to simplify the application, the percentiles of inverse Gaussian distribution with CV = 0.25 to 4 were calculated. Finally, this distribution was applied to occupational exposure data.

Within-Shift Variability of Short-Term Exposure to Organic Solvent in Indoor Workplaces

This study examined the degree of within-shift variability of short-term exposure concentrations for workers exposed to organic solvents in indoor workplaces. For this purpose, 117 exposure data sets of 15-minute time-weighted average (15-min TWA) and those of 60-min TWA were collected from 53 workers employed in the offset printing, gravure printing, screen printing, machine control board production, fiber-reinforced plastic production, hard metal production, electrical parts production, and chemical synthesizing industries. Data analysis showed that the tenth, fiftieth, and ninetieth percentiles of the geometric standard deviations of 15-min TWA values [GSD(15m)] were 1.4, 2.3, and 4.5, respectively; and those of GSD(60m) were 1.2, 1.7, and 3.4, respectively. Based on an assumption of lognormal exposure distribution, the maximum values of 15-min TWA (the 98.4th percentile) were estimated to be 4.3, 36, and 650 times as high as the minimum one (the 1.6th percentile) for the low, middle, and high exposure variabilities, respectively; and to be 2.0, 4.3, and 8.2 times the 8-hour TWA value, respectively. Consequently, when the 8-hour TWA exceeds 0.23 times (1/4.3) the short-term exposure limit value, the high short-term exposure condition should be evaluated. The maximum values of 60-min TWA (the 93.8th percentile) were estimated to be 1.8, 5.1 and 43 times as high as the minimum one, respectively; and to be 1.3, 2.0, and 3.1 times the 8-hour TWA value, respectively. The relationship between production factors and within-shift exposure variability was also examined. The intermittent solvent use group had significantly higher median values of GSD(15m) and GSD(60m) than the continuous group. The mobile pollutant source group had a significantly higher median value of GSD(60m) than the stationary group.

Interior Air Pollution in Automotive Cabins by Volatile Organic Compounds Diffusing from Interior Materials: II. Influence of Manufacturer, Specifications and Usage Status on Air Pollution, and Estimation of Air Pollution Levels in Initial Phases of Delivery as a New Car

Air pollution in the cabins of 101 Japanese cars due to organic compounds diffusing from the interior materials has been described in our previous report. In the present study, the influence of the manufacturer, specifications and usage status of these cars on the interior air pollution was evaluated by covariance analysis. Also, the levels of air pollution in the initial phases of delivery as a new car were estimated using previous data for the time-courses of interior concentrations of organic compounds measured in another new car. The findings showed greater air pollution in the cabins of luxury cars, with leather seats or leather steering wheels, or high-end catalogue prices. Differences in the specifications contributed more markedly to interior air pollution than differences in manufacturers. Also, usage status, such as everyday ventilation affected the long-term interior air quality. The sum values of interior concentrations of 154 compounds, for which there were time-course data, were estimated to be approximately 1700 μg·m-3 as a median (max. 11,000 μg·m-3) at 1 month from delivery (interior temperature, 32°C; interior humidity, 45%).

Load on the low back of teachers in nursery schools

In order to evaluate the load on the low back of teachers in nursery schools, basic activity, working posture, child-lifting, and desk-lifting were analyzed for eight nursery teachers using video recording. The trunk inclination angle (TIA) was also measured continuously during full workshifts for 20 nursery teachers using an inclination monitor. The nursery teachers in the 0–1 (year) age class more often adopted low working postures, “sitting on the floor” and “kneeling,” while teachers in the 4–5 age class more frequently adopted high working postures, “standing” and “sitting on a chair.” The mean of TIA among all subjects was 20°. The time spent at a TIA of more than 20° represented 43% of the workshift. The mean and time distribution of TIA did not differ between the age classes. The frequency of trunk-lifting from severe bending forward (TIA > 45°) was 86 times/hour on average. The frequency of trunk-lifting was highest in the 0–1 age class. The number of times of child-lifting was 46 in the 0–1 age class, while it was 1 in the 4–5 age class.

Identification of urinary metabolites of human subjects exposed to o-dichlorobenzene

Abstracto-Dichlorobenzene (o-DCB) has adverse effects on the liver and kidney in animals. It also causes some irritation to the eyes and the upper respiratory system in humans. This study aimed to identify urinary metabolites of human subjects exposed too-DCB. Urine samples were collected from three male workers exposed too-DCB and were analyzed using a gas chromatograph-mass spectrometer. 2,3- and 3,4-dichlorophenols and 3,4- and 4,5-dichlorocatechols were detected in the all samples. Some amounts of the four metabolites were presumably present as conjugates, because they increased after heating with hydrochloric acid.